<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>let-实践案例</title>
    <style>
      .container {
        margin-top: 30px;
      }
      .page-header {
        margin-bottom: 20px;
      }
      .item {
        width: 80px;
        height: 40px;
        border: 1px solid #000;
        display: inline-block;
      }
    </style>
  </head>
  <body>
    <div class="container">
      <h2 class="page-header">点击切换颜色</h2>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
    </div>

    <script>
      let items = document.getElementsByClassName("item");

      for (let i = 0; i < items.length; i++) {
        items[i].onclick = function () {
          items[i].style.background = "pink";
        };
      }
    </script>
  </body>
</html>
